Cancer surgery, malignant invasion, infection, congenital malformation, amongst other causes may impede lymph flow, resulting in blockage, pain, grotesque deformity and limb immobilization. Treatment utilizes compression to remove pooled lymph. Currently, lymph transport is not measured, but is indirectly assessed subjectively on: pain alleviation, mobility, etc. Quantitation of fluid movement is needed and could be invaluable for tailoring treatment modes. This project proposes a quantitative assay of lymph movement by non-invasive, differential dual beam absorptiometry, developed at this laboratory. A Cadmium-109 scanner (22 and 88 keV photons) will be used for upper limbs. Iodine-125 and Americium-241 (27, 35 and 60 keV photons) will be fabricated into a second scanner for edematous calf and thigh measurements. Our overall objective is to compile previously unavailable basic quantitative data on lymph transport during treatment, to enable the physician to quantitatively judge progress and to determine the usefulness of the current subjective assessments on the efficacy of treatment. In our preliminary studies we have made some progress towards this objective. An ancillary objective is to evauate the potential of differential absorptiometry for routine clinical assay, during lymphedema treatment. This project will: a) refine existing and fabricate a new dual beam device for lymph assay of the limbs; b) compile data on lymph transport and other anthropomorphic data, following 150 subjects suffering blockage and undergoing pressure treatment; c) establish rate and progress of lymph transport vis-a-vis current clinical 'pumping' regimens, and determine the appropriateness of the standard two week treatment period; d) compare lymph pool levels with clinical indices, such as pain and immobilization; e) correlate transport indices with older, less adequate measures of treatment assessment e.g., visual estimates of limb size. This study will provide: 1) a fund of basic scientific data dealing with lymph pooling and its treatment; 2) define more precisely the best treatment time; 3) provide the clinician with improved basis for judging treatment progress, possibly resulting in more rapid mobilization of the afflited limbs and lessened pain, deformity, and discomfort. The basic disciplines will be lymphology, oncology, radiation physics plus specialties involving the care of the cancer patient.